Sensitized photographic film, plate, and emulsion



Feb. 23, 1937. H. A. PIGGOTT ET AL T 2,071,899

SENSITIZED-PHOTOGRAPHIC FILM, FLATE, AND EMULSION Filed Dec. 4, 1935-SENSlTIVlTY RANGE 0 PHOTOGRAPHIC EMULSION TREATEDYWITH DYESTUFF 0FEXAMPLE SENSITIVITY RANGE OF PHOTOGRAPHIC EMULSION TREATED WITH DYESTUFF0F EXAMPLE INVENTQRS Henry Alfred P133011 Erna sTHaT'T-y Ru I ATTORNEYPatented Feb. 23, 1 937 I I I UNITED STATES PATENT OFFICE I SENSITIZEDllAlggt iiglg zlzlilgfi FILM, rm'rs,

Henry Alired Piggott, Cheadle Hulme, and Ernest Harry Rodd, Brooklands,England, assignors to Imperial Chemical Industries Limited, aoorporation of Great Britain Application December 4, 1935, Serial No.52,916 In Great Britain May 31, 1980 2 Claims. (01. 95-1) This inventionrelates to photographic sensitizthe metaand para-positions, R representsan in: compositions and to photographic preparaaliphatic hydrocarbonradical (not necessarily the tions, such as emulsions or plates or filmscoatedsame) Y represents the negative radical an with emulsions,comprising such compositions. acid (e. g., halogen, sulfate, oxalate,nitrate, chlo- This application is a continuation-in-part of rate, etc),and M represents a methenyl chain 5 our co-pendingapplication Serial No.540,810 which may or may not be substituted by monovafiled in the UnitedStates May 28,1931, and in lent auxochromic substituents, for instance,by Great Britain May 31, 1930. aikyl, alkoxy or aryl groups or byhalogen atoms It is known that a standard photographic emulsuch aschlorine, bromine or iodine. 1o sion is sensitive to light rays onlywithin the It willbe recognized that this formula may also wave-lengthrange of about 360 to 500 millimibe written:

crons, and'that by suitable treatment, e. g., by x z bathing ,aphotographic plate in a dilute solution 01 a sensitizer, the emulsionbecomes sensitive to light of other wave-lengths, but it is still amatter h I 15 or difliculty to increase or decrease the sensitivity B atwill in any desired degree. 1

It is an object of this invention to produce new i z and improvedsensitized photographic emulsions. X

A further object is to provide sensitizing compoj I/ N 20 sitions whichwill render photographic emulsions sensitive to light rays in the redand infra-red i; it,

region of the spectrum. It is a further object of this invention toprovide photographicemulsions sensitive to red and infra-red light rays.It is also e posmon f the acid residue Y is t it 25 an object of thisinvention to provide plates and 1y known and it may be in equilibriumbetween films coated with such sensitized emulsions. I the two nitrogenatoms, other Ohlects will appear in the descrlphm and In carrying ourinvention into practical eiIect, claimh- I we treat a photographicemulsion with unsym- T ese o i t are achieved according to this imetrical polymethine dyestuffs as described so vention by h mp y ofunsymmetrical above, e. g., by bathing a photographic plate in a p y mdyestuffs Such as can he Obtained by dilute aqueous solution oi'thedyestuii. The dyecondensing a heterocyclic nitrogen compound, t n maybedd d to typical photographic emulcon flinl al rn l iv methylene g psions, such as gelatino silver halide emulsions, in

5 with an intermediate compound obtainable by the a manner well known inthe art. Preferably, a pr c described in our British Patent N solutionof about 1 part of dyestufl in about 2000 344,409. In general, thesensitizing dyes employed parts of 50% aqueous alcohol is prepared. Thisin accordance with the pr n inv nii flnr stock solution is diluted foruse with about 20 characterized by having the G n f mul parts of water.Approximately 100 cc. 0! the di- 0 luted solution are then taken foreach full size 40 x photographic plate to be treated and the plate is 11CM=C I a, immersed in the solution which is agitated gently and kept incontact with the plate for a period 0! 4 about five minutes. The plateis then washed 5 R Y with water and dried. It will be apparent to thosewherein X represents a member oi the oxygen In the that the proportionsor dyestufl and photographic emulsion may be varied in group oi elementsor dialkylmethylene, Z repreorder to obtam the desired we 7 sents amember of the oxygen group of elements, The accompanying. drawingillustrates the Sam 5 dmkyl methylene. Vinylehe is diflereht sitivitycurves of photographic emulsions treated 5 from X, B1 and R2 representthe same or diflerent t certain of t unsymmetrical dyegtuflgortho-aromatic nuclei which may or may not be matter described.substituted by monovalent auxochromic substit- The invention will berurther illustrated but is uents, e. g., 'by alkyl and alkoxy groupsand/or not limited by the following examples, in which as halogen atomssuch as chlorine and bromine in the parts are by weight.

flux for ten minutes in The reaction In and was filtered oil and formula.When a photograph solution of the dyestufl became sensitive to 11 therange 01' An intermediate compound condensing 9 ethiodide and 66Twenty-four condensed w dolenine-methi teen minutes a solution 01' 50 patated dyestuii' purified It may be given the I Example I with 7 parts of1:

this product. were condensed 3-trimethyl-2-methyleneindoline by boilingthe two components under re- 2 parts 01' acetic anhyixture was thencooled,

ic plate was treated with a Esample II parts of acetic Example of our Bparts of hydride to which 5 .-'I'he or the formula:

When photographic treated with the dyest the sensitivit millimiem yrange is from was prepa ed by parts oi 2-methyl-benzothiaaoleparts oidiphenyl iormamidine anhydride. as described in ritish- Patent No.344,409. this product were then 18 parts or 2:8:8-trimethyl-inodide in160 parts of acetic anparts of sodium acetate had then diluted by orwater and the precipiby lixiviation with ether. ormula:

plates and emulsions are uir as previously described about 360 to aboutdide and 66 parts of was purified by lixiviation with An alternatemethod of preparing the dyestuil' is to produce the intermediatecompound from 2:3:3-trlmethyl-indolenine-methiodide and diphenyli'ormamidine, as described in Example 1 of our British An intermediateproduct was prepared by boiling 58 parts ofZ-methyl-benzoxazole-ethiodide 344,409. about 18 parts 2:33-trimethyl-indolenine-ethiodide under reflux in N/ or. 1 as,

When this dye is employed for sensitizing photographic plates andemulsions, as previously described, it extends the wave-length range andthe plate becomes sensitive to wave-lengths 01' light within the range01' 360 to about 600 milimicrons.

344.409, and then boil under reflux equi-molecular proportions oi saidcompound and 2-methylbenzoxazole-ethiodide in 160 parts of aceticanhydride and 5 parts or sodium acetate i'o'r fifteen minutes. Thedyestui! may be separated as previously described.

Example IV An intermediate compound boiling 90 parts was prepared by oi2-methyl-benzothiazole-ethio- Alternately, the dyestufl' may be preparedby making the intermediate product from 2-methyl benzoxazole-ethiodide,as described in Example 4 of our British Patent No. 344,409, and thencondensing equi-molecular proportions of this intermediate product and2-methyl-benzothiazoleethlodide in the presence of acetic anhydride andsodium acetate as previously described.

The dyestuii may be given the formula:

or the formula: n 0\ /s O-CH=CH-OH=C 0:134 \I I When photographic platesand emulsions are treated with the above identified dyestuff in themanner previously described, the range of sensi tivity to light isextended and the plate becomes chain. By

sensitive to a wave-length range from 360 to about 640 millimicrons.

It wil be apparent is applicable to the plates and emulsions dyestuffsof the type that the present invention treatment of photographic withother unsymmetrical described in the examples,

namely, those characterized by having dissimilar heterocyclic nucleiconnected by a methenyl dissimilar nuclei" we mean nuclei which aresubstantially different, either in having dissimilar hetero atoms (as,for instance, an oxazole, thiazole or selenazole nucleus) connectedthrough a methenyl chain to an indoline nucleus or a quinoline nucleus.Thus, in, Examples 11 and III, we have described dyestuffs in which athiazole and an oxazole nucleus are connected through a methenyl chainto an indoline nucleus. By substituting chemically equivalentproportions of 2- methyl-benzoselenazole-ethiodide 'tor2-methylbenzothiazole-ethiodide or 2-methyl-benzoxazoleethlodide inthese examples, it will be apparent that we can obtain dyestuil'scontaining a selenazole nucleus connected through a methenyl chain withan indoline nucleus, said dyestuffs also being characterized byexcellent sensitizing properties. Similarly, by neacting chemicallyequivalent proportions oi ethiodides of 2-methyl-benzoxazole,2-methyl-benzothiazole or 2-methylbenzo'selenazole with the quinaldineethlodide-diphenyl iormamidine condensation product of Example I inthepresence oi acetic anhydride and sodium acetate, we may prepare anoxazole, thiazole or selenazole nucleus connected through a methenylchain to a quinoline nucleus.

It will also be apparent that we may employ dyes containingvariouscombinatlons of oxazole,

selenazole and thiazole nuclei. Thus, our preterred dyes arethose inwhich the two heterocyclic nuclei are dissimilar in that they containdissimilar atoms irom the'oxygen group of elements. Such a dye isdescribed in Example IV in which a thiazole and an oxazole nucleus areconnected by a methenyl chain. Instead of Z-methyl-benzoxazole-ethlodide in Example IV, we may employ the chemicallyequivalentproportions of 2- methyl-benzoselenazole-ethiodide to produce a dye inwhich through amethenyi chain to a thiazole nucleus; or, we may preparethe intermediate compound from a-methyl-benzoxazole-ethiodide and didyescontaining a selenazcle nucleus is connected a dye containing an oxazoleand a selenazole nucleus connected by a methenyl chain.

For simplicity in describing the invention, we

1 have'heretoiore referred specifically to the unsubstitutedbenzoxazoles, benzothiazoles andbenzoselenazoles, but it will beapparent to those skilled in the art that dyestufis containingauxochromic substituents, such as halogen atoms (e. g., chlorine orbromine), alkyl groups (e. g.,

methyl, ethyl, iscpropyl, butyl and higher homologues), and/or allroxygroups (e. g., methoxy, ethoxy, butyloxy, etc.) may be present in thearomatic nucleus in anyposition, or positions, but the ortho positionswhich are already 'fully substituted by the bonds from the heterocyclicring. The method of preparing the dyestuffs from the substitutedderivatives is the same as from the-unsubstituted derivatives, exceptthat an intermediate is employed in which a substituent is alreadypresent. For instance, a 2- methyl-benzpselenazole ethlodide or' a2-methylbenzothiazole-ethiodide in which the position mm to the carbonatom connectedto the sele-, nium, sulfur or oxygen atom is occupied byan atom or group such as chlorine, bromine, methyl,

ethyl, methoxy or ethoxy. Instead of the aromatic nucleus of theoxazcle,selenazole or thiazole being a benzene nucleus, it maybe a naphthalenenucleus, either substituted or unsubstituted.

Unslymmetrical dyes or the type described conheterocyclic nucleiconnected 7 taining dissimilar by a pentawmethenyl chain may be preparedas described 'in our British Patent No. 355,693, by

reacting a beta-anilino-acrolein-anil and 2:3:3-

trimethyl-indoleni'ne allryl-icdide or Z-methyl- -benzothiazole-alkyiiodide or 2-"-methyl-.benzoselenazole -alkyl-iodide or2-methy1-benzoxazolealkyl-iodide'in acetic anhydrlde to form anintermediate compound, intermediate compound with a'z-methyl-benzothiazole-alkyl-iodlde,Z-methyl-benzoxazole-alkyl-iodideor Z-methyl-benzoselenazole-allwliodidein whic the member of the oxygen group of elements is dissimilar fromthat employed in the formation of the intermediate. This condensationmay be c 'ried out in the presence of acetic anhydride and sodiumacetate, as above described.

Unsymmetrical dyestuffs oi the type described containing substituents onthe methenyl chain ploying alpha-substituted may be prepared by ebeta-anilino-acroleinils invthe preparation of the intermediate bodiesin accordance with British Patent No. 355,693, and then reacting theintermediate with the desired 2-methyl-benzothiazole ethiodide,2-methyl-benzoxazole-ethiodide or 2-methyl-benzoselenazole-ethiodide,the choice of intermediate and/or reacting component being made so as toobtain a dye having, dissimilar heterocyclic nuclei. The dye is obtainedby reacting the intermediate, for example, an intermediate prepared byheating approximately equimolecular proportions oi lino-acrolein anil in200 parts of acetic anhydride to boiling 101' one hour as in Example 2 rBritish Patent No, 355,693, and then condensing the intermediate with anequi-molecular proportion and then condensing saidalpha-chloro-beta-aniof Z-methyl-benzothiazole-ethiodide or 2 methy1-benzoxazole-ethiodide or 2-methyl-benzoselenazole-ethiodide in aceticanhydride containing potassium acetate, as in Example 4 of said patent.The resultant dyestufi will have a chlorine atom substituted on themethenyl chain. By employing the corresponding alpha-alkyland alpha-.alkoxy-substituted beta-anilino-acrolein-anils or otheralpha-substituted derivatives, the corresponding substituents may beobtained on the methenyl chain. a

The course of reaction for the process of preparing the dyes asdescribed in the examples -may be illustrated by the followingequations:

(1) R/ Acid anhydride Diarylamidlne N NHCMH: R Y

CC H=CH N I l-Odin R Y O CH:

R1 +OaHsNHCOCHa Intermediate X (2) R( ;C CH=CH N-CuHg A Acid-bindinsubstance c. g, sodium acetate R1 0 wherein R, R1, R2, X, Y, Z and Mhave the fore going significance.

In the foregoing reactions, it will be recognized that equivalents maybe employed, for example,

propionic enhydride for acetic anhydride or sodium propionate for sodiumacetate. The for mation of the dye may also he effected in the presenceof pyridine, alcohol or other solvents.

Preferred dyestufls of the inventionare such as may be represented bythe general formula:

where A is a monovelent heterocyclic nitrogen residue of the type:

in which Ar and B have the some significance as before (though notnecessarily representing identical groups), whilst Z stands for --O, -Sor Se, or -CR: (R being alkyl) and is different from X.

It will be recognized that the results obtained with the 'difierentdyestuffs may vary. This is illustrated by the examples. The inventionhowever, ofl'ers a wide selection of dyestufls of a particular type withwhich it is possible to obtain new and improved sensitized photographicplates, films and emulsions.

As many apparently widely difl'erent embodiments of this invention maybe made without Acid anhydridc R:+e. g., acetic snhydrido-tdepartingfrom the spirit and Scope thereof, it is to be understood that we do notlimit ourselves to the specific embodiments thereof except as delined inthe appended claims.

We claim:

i. Photographic gelatino-silver halide emulsions containing anunsymmetrical polymethine ciyestufi having the following generalformula:

in which X represents a member of the oxygen group of elements ordielkyl methylene, R1 represents' an aryl radical of the benzene series,R represents an alkyl radical, and Y represents the negative radical ofan acid. 2. Photographic gelatino-silver halide emulsions containing anunsymmetrical polymethine dyestuif having the following general formula:

CH: CH

Ci ia I Y ALFRED PIGGOTT. nmms'r HARRY noon.

